Simplify floating-point comparisons with NaN in Optimizing.
This change was suggested by Ian.
Also, simplify some art::HFloatConstant and
art::HDoubleConstant methods.
Change-Id: I7908df23581a7f61c8ec79c290fe5f70798ac3be
diff --git a/compiler/optimizing/constant_folding.cc b/compiler/optimizing/constant_folding.cc
index b7a92b5..5a1d9b4 100644
--- a/compiler/optimizing/constant_folding.cc
+++ b/compiler/optimizing/constant_folding.cc
@@ -28,6 +28,7 @@
void VisitShift(HBinaryOperation* shift);
void VisitAnd(HAnd* instruction) OVERRIDE;
+ void VisitCompare(HCompare* instruction) OVERRIDE;
void VisitMul(HMul* instruction) OVERRIDE;
void VisitOr(HOr* instruction) OVERRIDE;
void VisitRem(HRem* instruction) OVERRIDE;
@@ -108,6 +109,26 @@
}
}
+void InstructionWithAbsorbingInputSimplifier::VisitCompare(HCompare* instruction) {
+ HConstant* input_cst = instruction->GetConstantRight();
+ if (input_cst != nullptr) {
+ HInstruction* input_value = instruction->GetLeastConstantLeft();
+ if (Primitive::IsFloatingPointType(input_value->GetType()) &&
+ ((input_cst->IsFloatConstant() && input_cst->AsFloatConstant()->IsNaN()) ||
+ (input_cst->IsDoubleConstant() && input_cst->AsDoubleConstant()->IsNaN()))) {
+ // Replace code looking like
+ // CMP{G,L} dst, src, NaN
+ // with
+ // CONSTANT +1 (gt bias)
+ // or
+ // CONSTANT -1 (lt bias)
+ instruction->ReplaceWith(GetGraph()->GetConstant(Primitive::kPrimInt,
+ (instruction->IsGtBias() ? 1 : -1)));
+ instruction->GetBlock()->RemoveInstruction(instruction);
+ }
+ }
+}
+
void InstructionWithAbsorbingInputSimplifier::VisitMul(HMul* instruction) {
HConstant* input_cst = instruction->GetConstantRight();
Primitive::Type type = instruction->GetType();